JP2005293653A - Optical disk device - Google Patents

Abstract

An optical disc apparatus capable of detecting a traverse load with higher accuracy than a conventional method is provided.
A tracking servo is turned on after a fixed voltage pulse voltage is applied to a traverse motor 3 from a system controller 5 for a certain period of time, and the number of tracks moved from a tracking error signal generated during that time is measured, and a traverse load is measured. The detecting means 7 detects the amount of movement, that is, the traverse load from the number of measurements, and can obtain an average load of the entire moving location without depending on the variation of the traverse load at one location, thereby detecting the traverse load with high accuracy. Yes. Further, the traverse movement amount can be calculated not from the number of traversed tracks but from the addresses before and after the movement.
[Selection] Figure 1

Description

  The present invention relates to an optical disc apparatus, and more particularly to an optical disc apparatus that detects a traverse load for moving an optical pickup and absorbs the load variation.

  The optical disk device is generally superior to other media such as a magnetic tape and a magnetic disk in terms of random accessibility, medium exchange, and storage. In recent years, optical disk devices have penetrated not only information-related fields but also consumer electronics fields, and the cost of optical disk devices has been reduced. As the number of component parts is reduced and the cost is reduced, the load variation of the traverse for moving the optical pickup is increasing, and it is required to absorb the load variation with high accuracy.

  Conventionally, an optical disc apparatus that detects a traverse load and absorbs load variations is disclosed in Japanese Patent Application Laid-Open No. 10-334473 of Patent Document 1, or a machine of a traverse mechanism according to a mechanical load variation or temperature change in Patent Document 1. Japanese Patent Laid-Open No. 2002-352447 of Patent Document 2 is known for the purpose of avoiding the influence of dynamic load fluctuations. Hereinafter, a conventional method for detecting a variation in traverse load disclosed in Patent Document 1 will be described with reference to the block diagram of FIG. 3 and the graph of FIG.

  In FIG. 3, the optical disk apparatus tracks an optical pickup 12 that irradiates a laser onto an optical disk 11 on which information is recorded and receives reflected light, a traverse 13 that moves the optical pickup 12, and a signal received by the optical pickup 12. A tracking error signal generating means 14 for detecting an error, a system controller 15 for determining the next operation from the signal detected by the tracking error signal generating means 14, and a control signal for driving the traverse 13 based on the determination of the system controller 15 are output. It comprises traverse control means 16.

The traverse load detection method of this optical disc apparatus will be described with reference to FIG. First, the system controller 15 measures the tracking error signal (graph b) from the optical pickup 12 with the focus servo and tracking servo enabled (ON) and the traverse servo disabled (OFF). The system controller 15 gradually increases the traverse motor voltage as shown in the graph a, and calculates the traverse servo from the applied voltage (starting voltage) vo and the level (movement amount) of the tracking error signal at the moment when the traverse mechanism moves at the time point to. The loop gain is calculated and determined. Since the loop gain of the traverse servo is determined from the error signal (movement amount) generated by disturbance (startup voltage) to the traverse mechanism, it is less susceptible to load fluctuations due to variations in parts of the traverse mechanism and environmental temperature changes. it can.
JP 10-334473 A JP 2002-352447 A

  However, in the conventional optical disk apparatus described above, since the load variation of the traverse is detected by a method of gradually increasing the voltage of the traverse motor at one place, the load detection accuracy is low, and therefore, the traverse load detection result itself varies, There is a problem that the variation in the traverse load cannot be absorbed stably.

  The present invention provides an optical disc apparatus that enables detection of a traverse load with higher accuracy than conventional methods.

  In order to solve this problem, in an optical disc apparatus according to the present invention, an optical pickup that irradiates a laser onto an optical disc on which information is recorded and receives reflected light, a traverse that moves the optical pickup, and the optical pickup receive light. Tracking error signal generating means for detecting a tracking error from the detected signal, a system controller for determining the next operation from the signal detected by the tracking error signal generating means, and a control signal for driving the traverse based on the determination of the system controller It comprises traverse control means for outputting and traverse load detection means for detecting the load of the traverse.

  With this configuration, the disk is started up until the tracking servo is turned on, a fixed peak voltage pulse voltage is given to the traverse motor from the system controller for a certain period of time, and the number of tracks moved from the tracking error signal generated at that time is measured. The amount of movement, that is, the traverse load can be detected from the measured number.

  In this configuration, the disk is started until the address can be read, the current address position is stored, a pulse voltage of a fixed peak value is given from the system controller to the traverse motor for a certain period of time, address read is performed after movement, It is also possible to detect the movement amount, that is, the traverse load from the front and rear address positions.

  According to the present invention, it is possible to detect a traverse load with higher accuracy than in the conventional method.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram of an optical disc apparatus according to Embodiment 1 of the present invention. The optical disk apparatus shown in FIG. 1 has an optical pickup 2 that receives a reflected light by irradiating a laser onto an optical disk 1 on which information is recorded, a traverse 3 that moves the optical pickup 2, and a signal that the optical pickup 2 receives. Tracking error signal generating means 4 for detecting a tracking error from the system, a system controller 5 for determining the next operation from the signal detected by the tracking error generating means 4, and a control signal for driving the traverse based on the determination of the system controller 5 And a traverse load detecting means 7 for detecting the load of the traverse 3.

  A traverse load detection method according to the first embodiment of the optical disc apparatus will be described with reference to FIG. First, the optical disk 1 on which information is recorded is activated, and the system controller 5 applies focus servo to the optical disk 1 with the optical pickup 2. At this time, the tracking servo may be applied, but the tracking servo is removed when the traverse load is detected.

  Thereafter, as shown in FIG. 2A, the system controller 5 applies a traverse drive pulse having a certain peak value and a constant period to the traverse 3 by the traverse control means 6 for a predetermined time. The pulse peak value / cycle and application time at this time are set so as to move even with a heavy traverse.

  Further, the actual moving amount is set to about 1 cm. This is to prevent an 8 cm diameter disk from penetrating the inner and outer peripheries, and the applied pulse should be determined with a light load among the mechanisms used. Here, as an example, if a pulse with a period of 100 Hz that moves even with the maximum load traverse as described above is applied for a time that causes a movement of about 1 cm with the minimum load traverse, the maximum applied traverse with the same applied pulse. A result of movement of about 0.5 cm was obtained. Of course, this result depends on the characteristics of the mechanism.

  By applying such a traverse drive pulse, the traverse 3 moves and traverses the track of the optical disc 1 in accordance with the amount of movement. Therefore, the tracking error signal generating means 4 performs tracking as shown in FIG. An error signal is generated.

  After applying the traverse drive pulse, tracking servo is applied at the timing when the traverse movement stops. Since the number of traversed tracks can be known from the tracking error signal during this time, the traverse load detecting means 7 can calculate the amount of traversal movement from the track pitch of the medium being reproduced. Since the magnitude of the traverse load and the traverse movement amount by the fixed drive pulse are inversely proportional, it is possible to detect the traverse load from this movement amount.

  According to this embodiment, compared to the conventional method, the average load of the entire moving part appears in the measurement result without depending on the load at one position, so that more accurate traverse load detection can be performed. It can be carried out. After detecting the traverse load, the result is stored in the system controller 5 and reflected in the settings of the traverse loop servo gain, traverse movement and traverse seek.

(Embodiment 2)
The second embodiment is also described with reference to a block diagram of the optical disk device used in the first embodiment. A traverse load detection method according to the second embodiment of the optical disc apparatus will be described with reference to FIG. First, the optical disk 1 on which information is recorded is activated, and the system controller 5 performs focus read / tracking servo on the optical disk 1 with the optical pickup 2 to perform address read, and stores the address of the current position. Thereafter, the system controller 5 applies a traverse drive pulse having a certain peak value and period as shown in FIG. 2A to the traverse 3 through the traverse control means 6 for a certain time. The pulse peak value / cycle and application time at this time are set so as to move even with a heavy traverse.

  In addition, the actual movement amount is about 1 cm. This is to prevent an 8 cm diameter disk from penetrating the inner and outer peripheries, and the applied pulse should be determined with a light load among the mechanisms used. Here, as an example, if a pulse with a period of 100 Hz that moves even with the maximum load traverse as described above is applied for a time that causes a movement of about 1 cm with the minimum load traverse, the maximum applied traverse with the same applied pulse. A result of movement of about 0.5 cm was obtained. Of course, this result depends on the characteristics of the mechanism.

  By applying such a traverse drive pulse, the traverse 3 moves and traverses the track of the optical disc 1 in accordance with the amount of movement. Therefore, the tracking error signal generating means 4 performs tracking as shown in FIG. An error signal is generated. After applying the traverse drive pulse, tracking servo is applied at the timing when the traverse movement stops. Thereafter, an address read is performed and the address after the movement is stored. The traverse load detection means 7 can calculate the amount of traverse movement from the addresses before and after the movement.

  Since the magnitude of the traverse load and the traverse movement amount by the fixed drive pulse are inversely proportional, the traverse load can be detected from this movement amount. Compared to the conventional method, the average load of the entire moving part appears in the measurement result without depending on the load at one position, so that it is possible to detect the traverse load with higher accuracy.

  Further, since the movement amount is calculated at the address position of the disk as compared with the method of the first embodiment, the second embodiment is more advantageous in a state where the quality of the tracking error signal is poor. After detecting the traverse load, the result is stored in the system controller 5 and reflected in the settings of the traverse loop servo gain, traverse movement and traverse seek.

  As described above, according to the present invention, since it does not depend on a single load as in the conventional traverse load detection method, an advantageous effect that a traverse load can be detected with high accuracy can be obtained. The availability is great.

1 is a block diagram of an optical disc apparatus according to an embodiment of the present invention. Explanatory drawing explaining operation | movement of the optical disk apparatus similarly Block diagram of a conventional optical disk apparatus using a traverse load detection method Explanatory drawing explaining operation | movement of the optical disk apparatus of the conventional traverse load detection system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 2 Optical pick-up 3 Traverse 4 Tracking error signal generation means 5 System controller 6 Traverse control means 7 Traverse load detection means

Claims (2)

An optical pickup that irradiates an optical disc with a laser and receives reflected light; and
A traverse for moving the optical pickup;
Tracking error signal generating means for detecting a tracking error from a signal received by the optical pickup;
A system controller for determining the next operation from the signal detected by the tracking error signal generating means;
Traverse control means for outputting a control signal for driving the traverse from the determination of the system controller;
Traverse load detection means for detecting the load of the traverse,
During reproduction of the optical disk, the system controller drives the traverse by outputting a fixed drive pulse from the traverse control means, and the traverse load detection means detects the amount of movement of the traverse from the detected tracking error signal. An optical disc apparatus for detecting a load. An optical pickup that irradiates an optical disc with a laser and receives reflected light; and
A traverse for moving the optical pickup;
Tracking error signal generating means for detecting a tracking error from a signal received by the optical pickup;
A system controller for determining the next operation from the signal detected by the tracking error signal generating means;
Traverse control means for outputting a control signal for driving the traverse from the determination of the system controller;
Traverse load detection means for calculating the amount of traverse movement from the address of the optical disc and detecting the traverse load;
When the optical disc is played, the traverse control means outputs a fixed drive pulse to drive the traverse, and the traverse load detection means calculates the amount of traverse movement from the address of the optical disc before and after driving to calculate the traverse load. An optical disc apparatus characterized by detecting.

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